Symptomatic vitamin A deficiency in a patient on long-term colesevelam

Introduction Bile acid sequestrants including colesevelam are increasingly used by gastroenterologists. The risk of fat-soluble vitamin deficiency when sequestrants are used is recognised. Vitamin A deficiency is uncommon in the UK, but delayed diagnosis can cause irreversible blindness. There are no guidelines for the monitoring of fat-soluble vitamin levels. Case discussion We describe a 63-year-old man who had a neuroendocrine tumour, treated with ileal resection and lanreotide and complicated by the development of severe bile acid malabsorption, pancreatic exocrine insufficiency and intermittent episodes of small intestinal bacterial overgrowth. Three and a half years after starting colesevelam, he developed progressive visual symptoms due to severe vitamin A deficiency. After diagnosis and parenteral vitamin A replacement, his visual symptoms improved but have not resolved. Conclusions Clinicians prescribing bile acid sequestrants should be aware that vitamin A deficiency may arise and should consider regular monitoring of serum levels.